I build a lot of walls, so I might be sensitive to this. I went back to my photo album (which, to my family's great frustration is about 1/3rd wall pics), most are out 1–2°; the exterior wall of the plaza is wavy, my pictures have a hard time capturing this. Most of the buildings in the plaza are out 1/2–1°, or more. Buildings are built plumb, because it is safe & easy. These buildings are straight but not plumb.